This invention is directed to a blood shut-off valve particularly for use in the outlet of heart-lung oxygenator equipment to automtically close the outlet line when the arterial reservoir is empty.
In an increasing number of surgical procedures, particularly in heart surgery, heart-lung oxygenators are used in an extra-corporeal circuit to maintain corporeal blood circulating during the procedure. Such oxygenators may include an oxygenation section in which oxygen is bubbled through the blood stream. Next is a defoaming section which separates the gas entrained from the liquid blood. Finally the blood is collected in an arterial reservoir at the outlet of the oxygenator.
From the outlet of the arterial reservoir, the blood flows gravitationally to the inlet of a peristaltic pump which delivers the arterial blood to the patient. Should the arterial flow reservoir in the oxygenator run dry, the arterial peristaltic pump would pump air into the patient, and death occurs almost instantaneously. It is thus necessary to shut off flow before the air is delivered to the patient.